1. Field of the Invention
This invention relates generally to the formation of thin layers and, more specifically, this invention relates an apparatus for preparing thin layers, such as gel layers useful in electrophoresis.
2. Description of the Prior Art
Among other purposes, thin gel layers are used in zone electrophoresis, especially for DNA sequencing, SDS gel electrophoresis (SDS PAGE) and isoelectric focusing. In these techniques small gel layer thicknesses are advantageous, since the temperature gradient over the layer thickness is small, and because the Joule heat per unit area and unit electric field are also small, therefore permitting high field strengths. Also, the time required for staining and destaining is relatively short when thin layers are used. Finally, because only small amounts of sample material are necessary with thin layers, sensitivity is enhanced.
In one known process of preparing gel layers, a liquid layer-forming material is poured from overhead into a perpendicularly arranged finished casting mold. However, this prior process has been found to be unsuitable for the preparation of bubble-free gel layers with a thickness of less than approximately 0.4 mm.